It is frequently desirable to manufacture articles out of flexible foam materials. In certain applications, such as in the assembly and manufacture of simple, unembossed, rectangular cushions, off-the-shelf foam which can be purchased in any desirable rectangular dimensions, can be used. Flexible foam, however, is elastic. When bent, twisted, or curved, flexible foam will tend to restore to its original shape.
Such foam cannot easily be deformed into a desired shape, such as having arcuate contours and the like. Thus, when an application calls for creating complex non-linear shaped articles, off-the-shelf rectangular foam blocks cannot be used using prior art manufacturing techniques. Rather, in the prior art, the manufacture of such shaped foam articles requires that the flexible foam block be cut, or carved.
For example, to make an article having sharp radii in the prior art, as the radii of the edges of a foam seat cushion, typically a rectangular foam block is provided to service as the cushion's base. Also, a second rectangular block which may be placed atop the first block is carved along its edges to accommodate the sharp, rounded radii of the cushion's edges. The carving of foam in this application is cumbersome and time consuming. Where complex shapes and multiple bends and curves are desirable, carving foam is even more difficult. It typically requires the use of special carving tools, and special skills are required to use these tools. Also, carving adds significantly to the cost and reduces efficiency for the mass production of foam articles.
It is also possible to manufacture flexible foam articles having multiple bends and curves by using molds. Of course, in this case it is not possible to take advantage of the availability of inexpensive off the shelf foam for manufacturing the article. Rather, a foam-forming compound is poured into the mold which has a suitable frame, webs and other design features for incorporation into the flexible foam article shape. This adds considerable expense to the manufacturing process.